Yea fuse I understand all that, what you call vaporize is do from the crank overheating. The crank is so hot the fuel vaporizes and the pressure is greater and thus making it run back into the tank.
Try a center exhaust deal, move the airfilter, and some people I know have cut out the left side window and used lexan to make a duct and move air to the back of the head and carb. Also the larger Zac project head helps.
I use Rb x12 5 port turbo and Richey RTU and RTO mugen mt12 engines, and I now have really no heating issues now.
I agree I wish someone did make a 5 port side exhaust engine, it would have saved me alot of time and money fixing the heating problem. The side exhaust engines seem to have no heating problems.